The admission of the UK prime minister to intensive care demonstrates how “indiscriminate” the virus is and how seriously the country should take the threat it poses, an expert has warned.

Prof Linda Bauld, Bruce and John Usher Chair in Public Health at the Usher Institute, University of Edinburgh, has said:

Anyone anywhere, including the most privileged in our society, can be affected and can become seriously ill. It is imperative now, more than ever that the rest of us comply with government guidelines to stay at home and not put others at risk.

Duncan Smith added that he has confidence in Raab and that contingencies for such a situation are well planned.

In terms of the government, we should not have any concerns at all. It has been known for some considerable time that the prime minister appointed Dominic Raab as first secretary. He is more than capable of fulfilling this role and he has great experience in government.

And he would have been brought up to speed on all the key processes that go around the prime minister since he became ill because they would have been planning for this and just in case this happened.

All the other cabinet ministers, some very senior like Michael Gove who understand how this works, they’ve all got important jobs to do … but what they will now have to do is look to Dominic Raab for that final principle decision making process whilst the prime minister is unable to take that role.

I feel completely confident for the government as it stands tonight, my concerns are for Boris Johnson, I have personal friends for a good friend.

Our thoughts are with him and his family because that’s the most important thing because at the end of the day this is a human issue as much as it is to do with the government.

He’ll be in great hands and I know that they will be taking no risks at all and that’s why they’ve done this so they can treat him properly.

My thoughts are with @BorisJohnson@carriesymonds and anyone who is or whose family is in a bad way due to #COVID19. This must be so scary. I hope the Government can now stop this pretence that all is fine and concentrate on getting him well and reassure the country

Iain Duncan Smith, a friend and colleague of the prime minister, has said he is “shocked with the news”. He has told the BBC:

I know him very well so I am deeply saddened really that it should come to this. He has obviously worked like mad to try and get through this but it’s not good enough so far.

It doesn’t mean necessarily that he isn’t going to pull through this because they may have put him on intensive care because they can treat him and he may have a secondary infection, a serious chest infection and that will stabilise him, they can get after it, and get him through this and out the other side quicker in a more stable way.

Let’s hope and pray Boris is in the best of hands and will pull through.

It is understood Johnson was moved to the intensive care unit just short of an hour and a half ago.

The decision was made by his medical team after his condition worsened over the course of Monday. The prime minister is understood to be conscious and to have been moved as a precaution in case he needs ventilation.

Israel will go into a four-day national lockdown starting on Tuesday to try to stem the outbreak during the Jewish holiday of Passover.

In a televised address, he said travel restrictions will be tightened and that Israelis will be banned from leaving their homes on Wednesday evening, when families traditionally travel to festive Passover “seder” meals.

In the UK, two more prisoners who tested positive have died. Each had underlying health conditions. A Prison Service spokesman has said:

A 46-year-old HMP Low Newton prisoner and a 59-year-old HMP Littlehey prisoner died in hospital over the weekend. Our condolences are with their families at this time. The Prisons and Probation Ombudsman has been informed.